Automatic controlling device for fluid-compressors.



E. HERR,

UTO'TG ONTRGLLNG DEVGE FOR FLUID GOPRESSOPS. APELIOATION FILED JUNE 2s,19708.

VJITNESE INVENTOFI readily lecjuaflises around the piston into inber thespringq` 18 holds the control valve l2 in position shown, in which theport 9 is open to chamber l5 the intercooler so'tliat the saine pressureists aamber i3 baclr oi' the discharge passage l2 which' leads to thesame intorcooler or space. Consequently the discharge valve' 8 or theErst compressor cylinder will operate in its usual manner to controlthe4 discharge of compressed air to the intercooler il, while the othercylinders -and pistons also operate in the 'usual and well known mannerto compress the air to the higher degree of pressure and force the sameinto the reservoir 8. As soon `the pressure in the reservoir reaches orrises slightly above the predetermined degree for which the spring 28 ofmy improved device is adjusted, the spring will be slightly compressedby the air pressure in chamber 26V and the stem 29 will open theregulating valve 2l thereby venting air from chamber l? to theatmosphere. By means of the lowering` of pressure on one side ot piston16, the intercooler pressure acting upon the other side in valve chamberl5 moves the piston and Slide valve 19 against the spring l to aposition in which the cavity 20 establishes connection from chamber 13and port 9 to port 2l and the atmosphere, whereupon the dis chargevalve, now having only atmospheric pressure upon its back, rises and isheld in its raised and open position seated against its cap by thepressure in passage l2 and the intercooler 4.

As the discharge valve 8 is held in its open position, it will bey seenthat no air will be taken into the cylinder of the iirst stage ofcompression, as the admission valve will not open against thepreponderance of pressure in the intercooler between the irst and secondstages of compression. lso proportion the clearances in the cylinders 2and 3 that these cylinders 'will be unloaded simultaneously'` with theunloading of the cylinder l.v l accomplish this by proportioning theclearances in the cylinder 2 so that the cylinder will not draw fluid'from the receiver 4 except when the cylinder l is worlring yat maximumcapacity, and by proportioning the clearances in the cylinder 3 so thatit will not draw fluid from the receiver 8 except when the cylinder 2 isdene tiret compressor cylinder as in i operation oli the governormechanism, the luid in the r ceiver 1; expands, during the operation cithe cylinder l, tlirougli the cylinder and the' receiver andconsequently' the pressure in the receiver drops and is onlyperiodically raised to the normal worlring pressure. lt, however, l"thecylinder 2 draws iluid from the receiver at the time or immediatelyafter the cylinder l is unloaded by the loperation or the governorvalve, the pressure in the receiver l will not rise to the normalpressure until the cylinder l is again in operation, and the cylinders 2and 3 will consequently be nnloaded. By unloading, l mean ythat theiiuid coniined in the cylinder will be irst compressed by the cylinderspiston and then expanded so as to impart energy to the piston. l mayalso gradually unload the cylinders 2 and 3 by proportioning theclearances in the cylinder 2 so that the cylinder will receive fluidfrom the receiver l after the valve 8 is raised and by maintaining theclearances in the cylinder 3 as above described. -`With such anarrangement, the load on the engine will be grad* ually decreased Afroma maximum to a very low minimum, at which the only work required tooperate the compressor will be that necessary to overcome the frictionot the machine. As soon as the cylinder l is unloaded, the pressure inthe receiver et starts to drop vand consequently the capacity of thecylinder 2 is reduced proportionately to the drop in pressure. -rlhereduction in the capacity of the cylinder 2 will cause a. correspondingreduction in the capacity of the cylinder 3. Thecapacities of thecylinders 2 and 3 will decrease until a predetermined pressure isreached in the receiver l, at which the cylinder 2 is unloaded. Caremust be taken to maintain a pressurein the receiver l Vsuch that thespring 18 cannot shift the controller valve i9 and cause hunting of thevalve 8. l

Shouldthe pressure in chamber 26, passage ll, and reservoir 6 decreasebelow thepredete'rmined amount, the tension of spring 28 will causespindle 29 to force diaphragm 2T inward, allowing the regulating pinvalve 2d to seat, and air pressure from chamber l5 will leak by pistonlinto chamber l?, passage'22, and chamber 23 until the pressures areequalized, when spring i8 will return piston lll and valve 19 to theposition as shown in Fig'. 2; thus allowing air 'from chamber l5 to passthrough port into chamber i3,z and as this pressure in chamber l5 isequivalent to ythe pressure obtaining in the intercooler l between thenrst and second stages of compression, it is apparent that' spring lllwill cause discharge valve 8 to seat as usual in the ordinary operationof compressors. Another c advantage of my invention is that there iseeaeiv no tendency for the governor valve to leak pressure except whenthe pressure in the main reservoir has exceeded the maximum workingpressure. rlhe chamber 25, to which the pipe l1 leads, -is air-tight,since it is closed by the diaphragm 27, and the chamber l? is alsoair-tight when the valve 2eisclosed. i

While l have described my improved-controlling valve mechanism aspreferably apilied to a three-stage air co1npressor,'it Will be evidentthat it is not limited to such construction but is equally applicable toany fluid compressor` ot' one or more stages, and in case oi a singlestage compressor the same ultimate reservoir pressure maybe connected toboth the diaphragm chamber and valve chamber oi the device.

l-laving lnovv 'described my invention, what l claim as new' and desireto secure by Letters Patent is l. A controlling device forduidcompressors comprisinga compressor discharge valve, a governing'device actuated by the pressure pumped by said compressor, a duidactuated reciprocatingV piston, a control valve actuated by said pistonand a regulat- -ing valve actuated by said governing device forcontrolling y'the operation of said piston.

2. A controlling device for duid compressors comprising a compressordischarge valve, a governing device actuated by the pressure pumped bysaid compressor, a control valve for delivering iiuid pressure behindsaid compressor valve and for exhausting pressure therefrom, a duidactuated reciprocatpiston oractuating said control valve and aregulating valve actuated by said governing device for exhausting Yduidpressure from behind said piston and causing said control valve to'exhaust :duid :trom behind said compressor valve. p v

' A controlling device tor duid compressors'comprising a compressordischarge valve, a governing device actuated by the'pressure pumped bysaid compressor, a tiuid actuated piston, means 'operated by said piston:for controlling the operation or said. discharge valve'and a regulatingvalve actuated by said governing device or controlling the operation orsaid.l piston.

li.- ln a multi-stage compressor, a primary stage, a governing mechanismcontrolled by final-stage pressure, a valve controlled by said mechanism.tor unloading the primary stage and a secondary stage, the clearancesof which areI so proportioned that the secondary stage is renderedineffective by the unloading of the primary stage.

5. ln a multi-stage compressor, a primary stage, a governing devicecontrolled by finalstage pressure for unloading, said primary stage anda secondary stage, the clearances of which vare so proportioned that thesecondary stage is rendered ineffective by the unloading of the primarystage.

6. .in a multi-stage compressor, a primary stage, a governing mechanismcontrolled by tinal-stage pressure, a discharge valve for said primarystage controlled by said mechanism to unload theprimary stage and aplurality ot' stages of successively increasing pressure, the clearancesof which are so proportioned that they are rendered inedeetive by theunloading of the primary stage.

7. n combination with a multi-stage compresser,y a governing mechanismcomprising a primary-stage discharge valve, a governing device actuatedby Vfinal-stage pressure, means for subjecting said discharge valve toprimary-stage pressure, a duid actuated reciprocating pistonorxcontrolling the operation oil said means and a regulating valveactuated by said governing device to control the operation oi` saidpiston.

8. ln combination with a multi-stage compressor, a governing mechanismcomprising a primary-stage discharge valve, a governing device actuatedby final-stage pressure,

vmeans i'or controlling the operation or said discharge valve, a duidactuated piston tor controlling the operation ci said means and aregulating valve actuated by said governing device to exhaust duid iroinbehind said piston to cause said piston to open said discharge valvethrough the agency or said means.

` 9, in combination vvith a multi-stage cornpressor, a governingmechanism comprising Aa primary-stage discharge valve, a governingdevice actuated by final-stage pressure, means subjected toprimary-stage pressure igor controlling the operation or said dischargevalve and a regulating valve actuated by said governing device iorcontrolthe operation or said means..

in testimony Avvluereot i have hereunto set my hand., i

' HERBERT il HERR.

Witnesses i?. iinvnsnnr, llnann lvl. Annen.

